Ireland ran in nine tries to overcome a spirited Russian side 62-12 in Rotorua.

Keith Earls led the assault with two tries with Fergus McFadden, Sean O'Brien, Isaac Boss, Andrew Trimble, Rob Kearney, Shane Jennings and Tony Buckley also breaching the whitewash. Man of the match Ronan O'Gara kicked a penalty and six conversions to finish with 15 points, missing just one shot at goal, and made good use of the space given to him by Russia.

O'Gara's performance, admittedly against weak opposition, has increased the pressure on first choice fly-half Jonathan Sexton, who slotted one conversion. Ireland did not have it all their own way with Vasily Artemyev and Denis Simplikevich scoring second-half tries for Russia.

They entered the match with the tournament's meanest defensive record have conceded just 16 points in two games, but their line was breached too easily. The result cements their position at the summit of Pool C and with one round left to play - against Italy in Dunedin next Sunday - they are on the brink of reaching the knockout stages.

It was a highly satisfying 80 minutes for a partially second string XV led by World Cup debutant Leo Cullen, who will hand the captaincy back to Brian O'Driscoll for Italy. Rain began to fall shortly after kick-off but the weather failed to prevent Ireland from making an ambitious start.

Sean O'Brien made an early impression with robust carries while Donnacha Ryan hit the line at pace, but the good work was undone when Buckley split the ball close to the line. Russia had strayed offside, resulting in three points for O'Gara, and their situation deteriorated further when fly-half Konstantin Rachkov was sin-binned for slapping the ball forward.

The first try arrived in the 10th minute, McFadden expertly touching down O'Gara's crossfield bomb after sliding over the whitewash. It was already looking grim for Russia, who conceded again just three minutes later when a series of carries ended with O'Brien piercing the last line of defence.

Russia burst into life in the 22nd minute, winning a turnover and then moving into Ireland's 22 through runs by centre Andrey Kuzin and number eight Victor Gresev. Their purple patch continued when winger Simplikevich snatched an O'Gara bomb from under the nose of Trimble and sped 30 yards.

Ireland's early assault had ground to a halt thanks to a mixture of Russian doggedness and their own lack of accuracy, exemplified by McFadden slinging a pass into touch. But as the half neared its conclusion, they found another gear, scoring three tries in four minutes.

Scrum-half Boss wriggled over from close range after Ireland had pounded at the Russian whitewash and then Earls worked an opening down the blindside with help from Trimble to score. With the try-scoring bonus point already secure, the Irish ran in a fifth for good measure with Trimble hacking ahead and diving on the ball.

Just six minutes of the second half had elapsed when Ireland scored their sixth try, Earls easily breaking through a tackle by Artem Fatakhov to gallop over. It was not all one-way traffic, however, with alert scrum-half Alexander Yanyushkin causing confusion in the Irish defence until Artemyev arrived to take the ball and score under the posts with Rachkov converting.

Ireland hit back with a lightening break from McFadden, but not for the first time they then fell foul of referee Craig Joubert's whistle at the breakdown. The Russians still looked dangerous when they had the ball in hand, a fact highlighted when Simplikevich rode two tackles to touch down in the corner.

Some loose passing - most notably from O'Gara - saw play switch from end to end until quick hands from Jamie Heaslip sent Kearney over. Heaslip was becoming increasingly influential, but it was substitute Jennings who scored next when he burrowed over from close range.

Ireland struck one final blow when Buckley forced his way across the line after Sexton had neglected an overlap.